Category not found error !!!

I created a policy and a policy category on SQL 2008. I want to evaluate to qsl 2000 and 2005 server via powershell. First run i got category which i created was not found error. So i created same category on sql 2005 server. And now i got category not found
error for sql 2000 server. What is the problem. ??

You need to make sure that you have applied the latest cumulative update to the instance acting as the Central Management Server. Microsoft just recently released CU7 for SP1.
http://support.microsoft.com/kb/979065/en-us